Based on the doc: https://docs.google.com/document/d/1d5alzMVxU6vfZaxcvVrJGr-G3_z4rHbCPkskfGtj1lw/edit?tab=t.0#heading=h.ll06elsrif5g

Category: Regional context (1).

Create a test that creates a resource (via Horizon UI), something simple like Flavor or Keypair and check that this is visible only for the region where it was created.